Strain Redistribution of Myocardial Blood

In addition to the obvious advantages of data compression for storage and retrieval of map data, the method also has significant advantages for analysis and comparison of maps. The 216 coefficients that uniquely characterize each map are a magnitude of information that is manageable by pattern recognition techniques and may permit automated classification of maps as a screening process. Map data expressed as 216 coefficients can be handled for statistical analyses aimed at quantitating the diagnostic utility of maps. Such analyses would be impossible for the 100,000 numbers that characterize a typical QRST map prior to data compression. Since QRS and ST-T data are represented separately—that is, 144 of the 216 coefficients represent QRS and 72 represent ST-T—it will be possible to apply pattern recognition techniques or other statistical analyses independently to QRS and ST-T data. This may be desirable since cardiac diseases may affect QRS and ST-T differently. It is not possible at this time to comment on the diagnostic utih'ty of the 216 coefficients since no standards exist for evaluating the diagnostic ability of any of the current map interpretation methods. However, studies are in progress to evaluate the diagnostic performance of these 216 coefficients.